Citation:

PANGAEA.996097 (dataset in review)

Name: Structural formula allocations and hydrothermal temperature estimates derived from vein-center chlorite compositions at the Onnuri Oceanic Core Complex
License: https://creativecommons.org/licenses/by/4.0/
Keywords: Chlorite geothermometry; Hydrothermal conduit cooling; Thermal decay

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Abstract:

Mineral structural formula re-calculations (atoms per formula unit, apfu) based on 28 oxygen equivalents and derived late-stage hydrothermal crystallization temperatures were obtained from vein-filling chlorite cores within the proximal metasomatic zones of the Onnuri Oceanic Core Complex, Central Indian Ridge, during the 2019 and 2022 R/V ISABU dredge operations (RD1912, RD1913, RD2208). The aim was to place precise thermodynamic constraints on the late-stage cooling profile of focused V1 hydrothermal conduits, defining the thermal baseline prior to crystallization-driven fracturing. EPMA major element datasets of vein-center chlorites were processed through structural inversion frameworks. Crystallization temperatures were computed and cross-validated using two independent geothermometers: the empirical AlIV-in-chlorite model of Cathelineau (1988) and the semi-empirical low-to-medium temperature thermodynamic approach of Bourdelle et al. (2013).

Keyword(s):

Chlorite geothermometry; Hydrothermal conduit cooling; Thermal decay

References:

Cation site occupancy in chlorites and illites as a function of temperature (1988). Clay Minerals, 23(4), 471-485, https://doi.org/10.1180/claymin.1988.023.4.13

Bourdelle, Franck; Parra, Teddy; Chopin, Christian; Beyssac, Olivier (2013): A new chlorite geothermometer for diagenetic to low-grade metamorphic conditions. Contributions to Mineralogy and Petrology, 165(4), 723-735, https://doi.org/10.1007/s00410-012-0832-7

Coverage:

Latitude: -11.420833 * Longitude: 66.407000

Minimum DEPTH, sediment/rock: 0 m * Maximum DEPTH, sediment/rock: 0 m

Event(s):

RD2208_DREG * Latitude: -11.420833 * Longitude: 66.407000 * Elevation: -2160.0 m * Method/Device: Dredge (DRG) * Comment: Geomorphology: Detachment fault surface. Lithology: Diabase, Serpentinite, Talc-rich metasomatite, Breccia

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Method/Device	Comment
1	Event label	Event		Choi, Sarang
2	DEPTH, sediment/rock	Depth sed	m	Choi, Sarang		Geocode
3	Lithology/composition/facies	Lithology		Choi, Sarang
4	Sample number	Sample no		Choi, Sarang
5	Point number	Point no		Choi, Sarang
6	Mineral phase	Mineral phase		Choi, Sarang
7	Texture	Texture		Choi, Sarang		Textural domain
8	Silicon dioxide	SiO2	%	Choi, Sarang		wt. %
9	Titanium dioxide	TiO2	%	Choi, Sarang		wt. %
10	Aluminium oxide	Al2O3	%	Choi, Sarang		wt. %
11	Chromium(III) oxide	Cr2O3	%	Choi, Sarang		wt. %
12	Iron oxide, FeO	FeO	%	Choi, Sarang		wt. %
13	Manganese oxide	MnO	%	Choi, Sarang		wt. %
14	Magnesium oxide	MgO	%	Choi, Sarang		wt. %
15	Calcium oxide	CaO	%	Choi, Sarang		wt. %
16	Sodium oxide	Na2O	%	Choi, Sarang		wt. %
17	Potassium oxide	K2O	%	Choi, Sarang		wt. %
18	Total	Total	%	Choi, Sarang		wt. %
19	Aluminium (IV) concentration in atoms per formula unit	Al(IV)	apfu	Choi, Sarang
20	Temperature, calculated	T cal	°C	Choi, Sarang	Calculated, chlorite geothermometer (Cathelineau, 1988)
21	Temperature, calculated	T cal	°C	Choi, Sarang	Calculated, chlorite geothermometer (Bourdelle et al., 2013)

License:

Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)

Status:

Curation Level: Enhanced curation (CurationLevelC)

Size:

228 data points

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